[Liaison]

Your Magellan must have the updated positioning/ outage information of the satellites and must be able to see 4 satellites at a time from constellation in order to give you proper 4 dimensional location for your unit. Being able to see 4 satellites gives you X-Y-Z axis coordinates and time so your GPS Receiver can update and give you proper positioning, navigation, and timing. Also having updated map data is critical in a format that the unit can read properly.

Other issues: GPS signal bounce can put you in the wrong location. If your GPS has been off for a long period of time, 24-48 plus hours, it can take 10-30 minutes for your GPS to rebuild the GPS constellation almanac (where the each satellite is in its orbit )before it can give you a proper location and be able to guide you on your way:

FIX: Either keep your unit constantly on with a unobstructed or limited obstruction view of the sky or put it outside 30 minutes before you begin traveling. It needs time to acquire information before the unit can help you get where you are going. Physical obstructions and terrain masking will always play havoc with signals not much you can do except do your best to understand the effects and don't get to upset with the GPS. Its only as good as the system limitations.

[SGCOS]

I don't use a GPS system, but that's a lot of information.

Thank You.

[Attention Surplus Disorder]

” If your GPS has been off for a long period of time, 24-48 plus hours, it can take 10-30 minutes for your GPS to rebuild the GPS constellation almanac..”

Had no idea, thanks for posting that.